The novel 6-dialkylaminoalkylamino-3,3,12-trimethyl-3,12-dihydro-7H-pyrano[2,3-c]acridine-7-ones 5-11 and their benzo [b]pyrano[2,3-h]acridine-7-one counterparts 12-18 were prepared by treatment of acronycine (1) or benzo[b]acronycine (4) with an excess of the appropriate dialkylaminoalkylamine. In both series, the introduction of a dialkylaminoalkylamino side chain at position 6 resulted in a significant increase of the cytotoxic activity against L1210 cells when compared with the parent compounds bearing a methoxy group, accompanied with an increased potency to arrest cells in the G2 + M phases of the cell cycle.